Primary objective is to study the relationships between times to and levels of intervention and medical outcomes by collecting data for 20,000 critical patients in 7 community hospital emergency departments in Los Angeles County. A classification of critical conditions already developed is to be refined by medical and other specialists, necessary forms for data collection developed and field tested, personnel trained and monitored, data processed and analyzed by appropriate computer programs. The usefulness of the new classification scheme will be compared with conventional disease categories. A computer model will be developed for predicting frequency of critical conditions based on demographic and other characteristics. Other statistical data will be collected useful for planning.